Increase exp rates drastically for this dungeon, if you want people to keep playing these, you need to give them an incentive, the exp is really poorly scaled at the moment, having to run through the whole thing (1 - 50) to level up about once at level 55 isn't that great, and if you want people to make people farm this more you really need a better incentive, also.
I disagree try getting a level in DF in an hour and a half post 55. Atm the weapon isn't the incentive for me, it is the exp that's the incentive and the weapon is just a bonus.